Computer systems often include devices that are positioned on a printed circuit board such that signal lines interfacing the devices are required to make 90.degree. or 180.degree. turns. FIG. 1 illustrates an example of a prior art technique for routing signal lines making 90.degree. degree turns. FIG. 1 shows a printed circuit board 100 having an electrical connector 110 that interfaces with an off-board component (not shown). Device 120 is mounted on the printed circuit board 100 and includes contacts (not shown) that interface with land pads 125-127 on the printed circuit board 100. The electrical connector 110 receives off-board signals that are transmitted to the land pads 125-127. The signals must be routed on signal lines making a 90.degree. turn from the electrical connector 110 to the land pads 125-127.
Signal lines 130, 140, and 150 route signals from the electrical connector 110 to the land pads 125-127. The signal line 130 includes a first section 131 on a first layer 160 of the printed circuit board 100 that connects a first location on the electrical connector 110 to a first via 135 on the first layer 160 of the printed circuit board 100. The signal line 130 includes a second section 132 on a second layer (not shown) of the printed circuit board 100 that connects the first via 135 to the land pad 127. The signal line 140 includes a first section 141 on the first layer 160 of the printed circuit board 100 that connects a second location on the electrical connector 110 to a second via 145 on the first layer 160 of the printed circuit board 100. The signal line 140 includes a second section 142 on the second layer of the printed circuit board 100 that connects the second via 145 to the land pad 126. The signal line 150 includes a first section 151 on the first layer 160 of the printed circuit board 100 that connects a third location on the electrical connector 110 to a third via 155 on the first layer 160 of the printed circuit board 100. The signal line 150 includes a second section 152 on the second layer of the printed circuit board 100 that connects the third via 155 to the land pad 125.
In the past when two layers of a printed circuit board were used for routing 90.degree. signal lines, the signal lines were routed one direction on a first layer and would make a 90.degree. turn at via "T" points on the second layer. The vias were typically packed close together to minimize the amount of space the signal lines would occupy on the printed circuit board. The vias would be placed without taking into consideration their affect on the length of their corresponding signal line. As a result, as illustrated in FIG. 1, the length of the signal lines 130, 140, and 150 would differ in length. The length of a signal line affects the electrical delay and capacitance on the signal line. Differences in electrical delay and capacitance between signal lines may adversely effect the performance of devices connected to the signal lines that operate at high speeds.